This Article Full Text Full Text (PDF) All Versions of this Article: biophysj.106.101295v1 92/12/4209    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Leontiadou, H. Articles by Marrink, S.-J. Search for Related Content PubMed PubMed Citation Articles by Leontiadou, H. Articles by Marrink, S.-J.

Ion Transport across Transmembrane Pores

Hari Leontiadou ^*, Alan E. Mark  and Siewert-Jan Marrink ^*

^* Groningen Biomolecular Sciences and Biotechnology Institute, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4 9747 AG, Groningen, The Netherlands; and School of Molecular and Microbial Sciences and the Institute for Molecular Biosciences, University of Queensland, Brisbane QLD 4072, Australia

Correspondence: Address reprint requests to Siewert-Jan Marrink, E-mail: s.j.marrink{at}rug.nl.

To study the pore-mediated transport of ionic species across a lipid membrane, a series of molecular dynamics simulations have been performed of a dipalmitoyl-phosphatidyl-choline bilayer containing a preformed water pore in the presence of sodium and chloride ions. It is found that the stability of the transient water pores is greatly reduced in the presence of the ions. Specifically, the binding of sodium cations at the lipid/water interface increases the pore line tension, resulting in a destabilization of the pore. However, the application of mechanical stress opposes this effect. The flux of ions through these mechanically stabilized pores has been analyzed. Simulations indicate that the transport of the ions through the pores depends strongly on the size of the water channel. In the presence of small pores (radius <1.5 nm) permeation is slow, with both sodium and chloride permeating at similar rates. In the case in which the pores are larger (radius >1.5 nm), a crossover is observed to a regime where the anion flux is greatly enhanced. Based on these observations, a mechanism for the basal membrane permeability of ions is discussed.

This article has been cited by other articles:

				H. Jang, B. Ma, R. Lal, and R. Nussinov Models of Toxic {beta}-Sheet Channels of Protegrin-1 Suggest a Common Subunit Organization Motif Shared with Toxic Alzheimer {beta}-Amyloid Ion Channels Biophys. J., November 15, 2008; 95(10): 4631 - 4642. [Abstract] [Full Text] [PDF]

				S.-J. Lee, Y. Song, and N. A. Baker Molecular Dynamics Simulations of Asymmetric NaCl and KCl Solutions Separated by Phosphatidylcholine Bilayers: Potential Drops and Structural Changes Induced by Strong Na+-Lipid Interactions and Finite Size Effects Biophys. J., May 1, 2008; 94(9): 3565 - 3576. [Abstract] [Full Text] [PDF]